U.S. patent application number 11/641356 was filed with the patent office on 2007-07-05 for method and apparatus for investigating a borehole with a caliper.
Invention is credited to John A. Hayes.
Application Number | 20070153626 11/641356 |
Document ID | / |
Family ID | 38050082 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070153626 |
Kind Code |
A1 |
Hayes; John A. |
July 5, 2007 |
Method and apparatus for investigating a borehole with a
caliper
Abstract
Embodiments of the present invention relate to a caliper and
method for mapping the dimensions and topography of a formation
such as the sidewall of a borehole. Examples of formations in which
embodiments of the invention can be used include, but are not
limited to, an oil, gas, pile borehole or barrette that has been
drilled or excavated into the earth.
Inventors: |
Hayes; John A.;
(Gainesville, FL) |
Correspondence
Address: |
SALIWANCHIK LLOYD & SALIWANCHIK;A PROFESSIONAL ASSOCIATION
PO BOX 142950
GAINESVILLE
FL
32614-2950
US
|
Family ID: |
38050082 |
Appl. No.: |
11/641356 |
Filed: |
December 18, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60751361 |
Dec 16, 2005 |
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Current U.S.
Class: |
367/27 |
Current CPC
Class: |
E21B 47/085 20200501;
G01V 1/46 20130101; E21B 47/01 20130101; E02D 1/02 20130101 |
Class at
Publication: |
367/027 |
International
Class: |
G01V 1/00 20060101
G01V001/00 |
Claims
1. An apparatus for investigating a formation, comprising: a
caliper adapted to be lowered into a formation such that an axis of
the caliper is substantially parallel with the longitudinal axis of
the formation, wherein the caliper comprises: a transmitter for
transmitting a transmitted pulse signal; a detector for detecting a
reflected pulse signal, wherein the reflected pulse signal is the
transmitted pulse signal reflected from a target location on a
surface of the formation onto which the transmitted pulse signal is
incident; a means for determining the time interval between the
transmission of the transmitted pulse signal and the detection of
the reflected pulse signal, wherein the distance from the
transmitter to the target location on the surface of the formation
and back to the detector is the time interval between the
transmission of the transmitted pulse signal and the detection of
the reflected pulse signal times the speed of the first pulse
signal; a means for rotating the transmitter and the detector with
respect to the axis of the caliper, wherein rotation of the
transmitter and the detector causes the target location on the
surface of the formation onto which the transmitted pulse signal is
incident to rotate with respect to the axis of the caliper.
2. The apparatus according to claim 1, wherein the formation is a
borehole.
3. The apparatus according 1, further comprising: a means for
raising and lowering the caliper in the formation, wherein raising
and lowering the caliper in the formation causes the target
location on the surface of the formation to raise and lower,
respectively.
4. The apparatus according claim 3, further comprising: a means for
controlling the rotation of the transmitter and detector and the
raising and lowering of the caliper such that the first pulse
signal is incident on a plurality of target locations on the
surface of the formation, and a means for producing a
representation of a portion of the formation corresponding to the
plurality of target locations on the surface of the formation onto
which the transmitter signal is incident.
5. The apparatus according to claim 3, further comprising: one or
more guide cables for guiding the caliper as the caliper is raised
and/or lowered in the formation, wherein the one or more guide
cables allow the position of the caliper to be controlled as the
caliper is raised and/or lowered in the formation.
6. The apparatus according to claim 1, wherein the transmitter
comprises a laser light source.
7. The apparatus according to claim 1, wherein the transmitter
comprises a sonar head.
8. The apparatus according to claim 5, wherein the one or more
guide cables are weighted to fall plumb into the formation.
9. The apparatus according to claim 8, wherein at least one of the
one or more guide cables is weighted with an inclinometer for
providing an output signal indicative of the orientation of the at
least one guide cable.
10. The apparatus according to claim 5, further comprising a means
for raising and/or lowering the caliper up and down the at least
one of the one or more guide cables by gripping on the at least one
guide cable.
11. The apparatus according to claim 5, wherein the caliper is
attached to at least one of the one or more guide cables, wherein
the means for raising and lowering the caliper comprises a means
for raising and lowering the at least one guide cable attached to
the caliper such that raising and lowering the at least one guide
cable attached to the caliper raises and lowers the caliper.
12. The apparatus according to claim 5, wherein the means for
raising and lowering the caliper comprises a cable attached to the
caliper.
13. The apparatus according to claim 10, wherein one or more of the
one or more guide cables and the cable comprise a conductor for
transmitting commands and/or power to the caliper and for receiving
data back from caliper.
14. The apparatus according to claim 1, wherein the caliper further
comprises a compass.
15. The apparatus according to claim 1, wherein the caliper further
comprises a gyroscopic stabilizer.
16. The apparatus according to claim 1, further comprising a means
for determining the speed of the transmitted pulse signal.
17. The apparatus according to claim 16, wherein the means for
determining the speed of the transmitted pulse signal comprises an
object a known distance from the transmitter wherein the speed of
the transmitted pulse signal is the distance from the transmitter
to the object and back to the detector divided by the time interval
between the transmission of the transmitted pulse signal and the
detection of the reflected pulse signal from the object.
18. The apparatus according to claim 7, wherein the sonar head
transmits in the range 50 kHz-300 kHz.
19. The apparatus according to claim 7, wherein the sonar head
transmits in the range 500 kHz-800 kHz.
20. The apparatus according to claim 7, wherein the sonar head
transmits in the range 1.0 MHz-1.5 MHz.
21. The apparatus according claim 1, further comprising a means for
determining the density of a fluid the transmitted pulse signal
travels into the target location.
22. The apparatus according to claim 21, wherein the means for
determining the density of the fluid the transmitted pulse signal
travels in comprises a pressure measuring device.
23. The apparatus according to claim 1, wherein the caliper further
comprises an inclinometer.
24. An method for investigating a formation, comprising:
positioning a caliper into a formation such that an axis of the
caliper is substantially parallel with the longitudinal axis of the
formation, transmitting a transmitted pulse signal from a
transmitter on the caliper; detecting a reflected pulse signal with
a detector on the caliper, wherein the reflected pulse signal is
the transmitted pulse signal reflected from a target location on a
surface of the formation onto which the transmitted pulse signal is
incident; determining the time interval between the transmission of
the transmitted pulse signal and the detection of the reflected
pulse signal, wherein the distance from the transmitter to the
target location on the surface of the formation and back to the
detector is the time interval between the transmission of the
transmitted pulse signal and the detection of the reflected pulse
signal times the speed of the first pulse signal; rotating the
transmitter and the detector with respect to the axis of the
caliper, wherein rotation of the transmitter and the detector
causes the target location on the surface of the formation onto
which the transmitted pulse signal is incident to rotate with
respect to the axis of the caliper.
25. The method according to claim 24, wherein the formation is a
borehole.
26. The method according 24, further comprising: raising and
lowering the caliper in the formation, wherein raising and lowering
the caliper in the formation causes the target location on the
surface of the formation to raise and lower, respectively.
27. The method according claim 26, further comprising: controlling
the rotation of the transmitter and detector and the raising and
lowering of the caliper such that the first pulse signal is
incident on a plurality of target locations on the surface of the
formation, and producing a representation of a portion of the
formation corresponding to the plurality of target locations on the
surface of the formation onto which the transmitter signal is
incident.
28. The method according to claim 26, further comprising: guiding
the caliper on one or more guide cables as the caliper is raised
and/or lowered in the formation, wherein the one or more guide
cables allow the position of the caliper to be controlled as the
caliper is raised and/or lowered in the formation.
29. The method according to claim 24, wherein the transmitter
comprises a laser light source.
30. The method according to claim 24, wherein the transmitter
comprises a sonar head.
31. The method according to claim 28, wherein the one or more guide
cables are weighted to fall plumb into the formation.
32. The method according to claim 31, wherein at least one of the
one or more guide cables is weighted with an inclinometer for
providing an output signal indicative of the orientation of the at
least one guide cable.
33. The method according to claim 28, further comprising raising
and/or lowering the caliper up and down the at least one of the one
or more guide cables by gripping on the at least one guide
cable.
34. The method according to claim 28, wherein the caliper is
attached to at least one of the one or more guide cables, wherein
raising and lowering the caliper comprises raising and lowering the
at least one guide cable attached to the caliper such that raising
and lowering the at least one guide cable attached to the caliper
raises and lowers the caliper.
35. The method according to claim 28, wherein raising and lowering
the caliper comprises raising and lowering the caliper via a cable
attached to the caliper.
36. The method according to claim 33, further comprising
transmitting commands and/or power to the caliper and for receiving
data back from caliper via a conductor in one or more of the one or
more guide cables and/or the cable.
37. The method according to claim 24, wherein the caliper further
comprises a compass.
38. The method according to claim 24, wherein the caliper further
comprises a gyroscopic stabilizer.
39. The method according to claim 24, further comprising
determining the speed of the transmitted pulse signal.
40. The method according to claim 39, wherein determining the speed
of the transmitted pulse signal comprises positioning an object a
known distance from the transmitter wherein the speed of the
transmitted pulse signal is the distance from the transmitter to
the object and back to the detector divided by the time interval
between the transmission of the transmitted pulse signal and the
detection of the reflected pulse signal from the object.
41. The method according to claim 30, wherein the sonar head
transmits in the range 50 kHz-300 kHz.
42. The method according to claim 30, wherein the sonar head
transmits in the range 500 kHz-800 kHz.
43. The method according to claim 30, wherein the sonar head
transmits in the range 1.0 MHz-1.5 MHz.
44. The method according claim 24, further comprising determining
the density of a fluid the transmitted pulse signal travels into
the target location.
45. The method according to claim 44, wherein determining the
density of the fluid the transmitted pulse signal travels in
comprises measuring the pressure in the fluid the transmitted pulse
signal travels in.
46. The method according to claim 24, wherein the caliper further
comprises an inclinometer.
47. The method according to claim 24, wherein the formation has a
diameter in the range 1.5 feet to 20 feet.
48. The method according to claim 24, wherein the formation has a
diameter in the range 3 feet to 12 feet.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/751,361, filed Dec. 16,
2005, which is hereby incorporated by reference herein in its
entirety, including any figures, tables, or drawings
BACKGROUND OF INVENTION
[0002] When formations such as boreholes are drilled or otherwise
created into earth, the actual shape of the formation, including
dimensions and/or topology, can be useful information to have prior
to filling the formation. The formation can be filled with, for
example, concrete and/or other materials to form a pile or other
structure. As such piles are often used to form the foundations of
buildings or other large structures. As such the piles are often
tested to determine the load-bearing capacity of the pile and the
tests typically involve the incorporation of a device for
performing testing. The shape of the cross-section of the pile in
the region of the pile where the test device is positioned can
enhance the accuracy of the interpretation of the data from the
test device. In addition, the shape of formation can be useful to
determine if there are any major irregularities and/or determine
the potential interaction between the pier and the sides of the
formation when a load is applied. In addition, the accumulation of
cross-sectional shapes can be used to calculate the volume of the
formation.
[0003] Techniques for providing information regarding the shape of
formations have included lowering a sonar device in the formation
and obtaining two or more vertical lines of sonar readings along
the walls of the formation. However, such limited information can
miss important irregularities in the sides of the formation. In
addition, data from regions of the formation having dirty fluids
can be difficult to accurately interpret. In fact, the radial
diameters of the formations in regions with dirty fluids can appear
narrower than they actually are due to the effects of the
particulates in the fluid on the sonar signals.
[0004] Accordingly, there is a need in the art for a method and
apparatus that can provide accurate information regarding the
dimensions and/or topology of a formation such as a borehole,
especially when the formation is filled with opaque stabilizing
fluids whose density often varies with depth.
BRIEF SUMMARY
[0005] Embodiments of the present invention relate to a caliper and
method for mapping the dimensions and topography of a formation
such as the sidewall of a borehole. Examples of formations in which
embodiments of the invention can be used include, but are not
limited to, an oil, gas, pile borehole or barrette that has been
drilled or excavated into the earth. Such dimensional and
topographic information can allow more accurate interpretation of
test devices positioned in the pile created within the borehole and
can allow an accurate determination of the volume of concrete
needed to fill the pile. Such information can also allow more
accurate projections of the interaction of the side of the pile
with the side of the borehole, especially when the formation is
filled with opaque stabilizing fluids whose density often varies
with depth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a longitudinal cross-sectional view of a borehole
with an embodiment of a caliper in accordance with the present
invention in the borehole.
DETAILED DISCLOSURE OF THE INVENTION
[0007] Embodiments of the present invention relate to a caliper and
method for mapping the dimensions and topography of a formation
such as the sidewall of a borehole. Examples of formations in which
embodiments of the invention can be used include, but are not
limited to, an oil, gas, pile borehole or barrette that has been
drilled or excavated into the earth. Such dimensional and
topographic information can allow more accurate interpretation of
test devices positioned in the pile created within the borehole and
can allow an accurate determination of the volume of concrete
needed to fill the pile. Such information can also allow more
accurate projections of the interaction of the side of the pile
with the side of the borehole.
[0008] FIG. 1 shows one embodiment of caliper 10 suspended in
borehole 12 by cable 14. Borehole 12 penetrates earth formation 16.
One or more guide cables 18 can also be suspended down into
borehole 12. In one embodiment, two guide cables 18 are parallel to
each other and are weighted 42 to fall plumb into borehole 12. In
one embodiment, one or more cables 14, 18 include a conductor for
transmitting commands and/or power to caliper 10 and for receiving
data back from caliper 10. Caliper 10 can be raised and lowered on
cable 14 by draw works 20, moving slidably along guide cables 18.
Guide cables 18 are raised and lowered independently of cable 14,
by draw works 22. In one embodiment, all guide cables 18 are
coordinated by being raised and lowered by a single draw work
assembly 22. Draw works 20, 22 can be of any type known in the art,
including pulley systems. Draw works 20, 22 are typically installed
at ground level 24. In an embodiment, draw works 20 and 22 are
connected to a common frame structure. In further embodiments, draw
works 20 and 22 can be such that the raising and lowering of a
plurality of cables 18 is in unison.
[0009] In one embodiment, guide cables 18 are suspended
independently of cable 14, which carries caliper 10. This
arrangement allows for greater positional control of guide cables
18. Positional control of guide cables 18 is desirable for
preventing contact between caliper 10 and interior wall 26 of
borehole 12 as caliper 10 descends and ascends, guided by guide
cables 18. Positioning guide cables 18 in borehole 12 and then
lowering caliper 10 as caliper 10 is guided by guide cable 18 can
allow a more accurate determination of the position of caliper 10.
In an alternative embodiment, cable 14 can be removed and caliper
10 can incorporate means for moving caliper 10 to propel itself up
and down by gripping on cables 18. Means for propelling up and down
a cable are known in the art and can be incorporated in caliper 10
for this purpose. In additional embodiments, caliper 10 can be
fixably attached to one or more cables 18 and the caliper 10
lowered by lowering cable 18 to which the caliper is fixably
attached and/or enabling caliper 10 to travel with respect to one
or more cable 18 to which the caliper 10 is not fixably attached.
In another embodiment, caliper 10 can incorporate a gyroscopic
stabilizer and an internal compass to allow the caliper 10 to be
raised and lowered without the use of guide cables 18.
[0010] Caliper 10 is insertable into opening 28 of borehole 12 and
can include sonar head 30 for transmitting acoustical energy toward
interior wall 26 of borehole 12. When the acoustic energy reaches
interior wall 26 the acoustic waves are reflected by interior wall
26 back to sonar head 30. Sonar head 30 detects the acoustic waves
and measures the elapsed time between transmission of the
acoustical energy and detection of the acoustic waves. From elapsed
time measurements, the distance from the sonar head to the interior
wall and back in a certain direction can be determined, allowing
determination of the location of interior wall 26 relative to sonar
head 30. Additional embodiments can incorporate a light source,
such as a laser source. This laser source can be used instead of
the sonar head 30 or in conjunction with sonar head 30. The laser
source can transmit a light beam toward interior wall 26 that can
be reflected by interior wall 26 and detected by caliper 10. Again,
by measuring the elapsed time between transmission and detection of
the light, the distance from the laser source to the interior wall
26 in a certain direction can be determined, allowing determination
of the location of the interior wall 26.
[0011] In one embodiment, caliper 10 includes a motor (not shown).
In one embodiment, caliper 10 includes gears and shafts for
enabling the motor to rotate sonar head 30. In various embodiments,
caliper 10 can include one or more of the following; gyroscope
stabilizer 32, internal inclinometer 34, internal compass 36, and
pressure measuring device. A pressure measuring device can measure
the pressure of the caliper's environment in the fluid in the
formation, where the pressure is a function of the depth and
density of the fluid and can, for example, be used to provide the
density of the fluid when the depth is known. In one embodiment, as
caliper 10 is raised or lowered in borehole 12, current is supplied
to the motor via cable 14 which connects caliper 10 to a generator
(not shown) on ground level 24. Other electrical signals can travel
down cable 14 and/or cable 18. In one embodiment, sonar head 30 is
rotated by the motor as caliper 10 advances along borehole axis 38.
Acoustic pulses emitted from sonar head 30 along borehole radius 40
can scan borehole wall surfaces 26 with such pulses emitted either
as the caliper 10 with sonar head 30 is continuously raised or
lowered, or at multiple fixed depths of the borehole that the sonar
head 30 is sequentially raised or lowered to. By rotating sonar
head 30 as the caliper 10 is raising or lowering, a spiral or
helical pattern of measurements can be accomplished, while allowing
continuous movement of the caliper 10 and the sonar head.
[0012] The speed of the caliper 10 raising or lowering can be
varied with time when, for example, it is desired to have more or
fewer measurements of a certain portion of the borehole. Likewise,
the rotation speed of the caliper head 10 can vary with time if,
for example, it is desired to have more or fewer measurements of a
certain portion of the borehole. A portion of the energy from each
acoustic pulse, or laser pulse, is reflected by wall surface 26 of
borehole 12 along radius 40 back toward sonar head 30, which
detects the reflected energy. The reflections contain information
relating to the topographic features and contours of walls 26 of
borehole 12. The number of measurements per unit area of bore hole
wall 26 can be controlled by controlling the speed of raising
and/or lowering sonar head 30 and/or controlling the rotation speed
of sonar head 30. In an embodiment, sonar head 30 rotates one full
rotation between advancement intervals of caliper 10 along borehole
axis 38. In this case, information is gathered in planar fields at
discrete locations along axis 38.
[0013] In one embodiment, electronic modules (not shown) on ground
level 24 transmit operating commands down borehole 12 and in
return, receives data back that may be recorded on a storage medium
of any desired type for concurrent or later manual or automated
processing. Data processor means, such as a suitable computer, may
be provided for performing data analysis in the field in real time.
In addition or in the alternative, the recorded data may be sent to
a processing center for post processing of the data.
[0014] Because borehole 12 may contain a fluid that changes in
density with changes in depth or other position, caliper 10 can be
calibrated to take these changes into effect. In one embodiment,
because the distance between sonar head 30 and each guide cable 18
is known and constant during a particular operation, a pulse can be
directed at a guide cable 18 and the time lapse between
transmission and detection measured. Changes in return speed at
different positions along axis 38 can be used to calibrate caliper
10 to take fluid properties into account to improve the accuracy of
the measurement of the distance from the sonar head 30 to the walls
26. In an embodiment, a pulse can be reflected from cable 18 for
each rotation of the sonar head 30 to provide calibration of the
speed of sound and/or light in the surrounding material for that
depth. In another embodiment, a sonar pulse and a laser pulse can
be reflected from a known location on or near the walls 26 and the
difference in the speed of sound and the speed of light in the
surrounding material can be used to calibrate the measurement
results for the surrounding material.
[0015] In one embodiment, multiple excitation frequencies are
available from which the operator can choose, depending on factors
such as the type and properties of fluid in borehole 12. The choice
of excitation frequency is a compromise between the need for signal
penetration through the borehole fluid using a longer-wavelength,
lower frequency pulse, more acoustic energy (the borehole fluid can
have undesirably attenuating effects at higher pulse frequencies)
and the need for spatial resolution that is achievable using
shorter wavelengths albeit at the expense of higher signal
transmission losses. Embodiments can utilize multiple frequencies
during the same measurement. A specific embodiment of the invention
pertains to measuring the physical characteristics of a borehole
having a diameter between 1.5 feet and 20 feet, and in another
embodiment between 3 feet and 12 feet. In one specific embodiment,
an excitation frequency in the range 50 kHz-300 kHz is used; in
another specific embodiment, an excitation frequency in the range
500 kHz-800 kHz is used; and in a further specific embodiment, an
excitation frequency in the range 1.0 MHz-1.5 MHz is used.
[0016] In one embodiment, an inclinometer 42, can be attached to
the end, or other location, of cable 18, rather than merely
weights. Thus, if guide cables 18 are not able to hang freely,
inclinometers 42 can provide an output signal indicative of the
orientation of the end of each guide cable 18 in the borehole 12.
This situation may be encountered where borehole 12 is not
sufficiently vertical, with respect to gravity, for example.
[0017] All patents, patent applications, provisional applications,
and publications referred to or cited herein are incorporated by
reference in their entirety, including all figures and tables, to
the extent they are not inconsistent with the explicit teachings of
this specification.
[0018] It should be understood that the examples and embodiments
described herein are for illustrative purposes only and that
various modifications or changes in light thereof will be suggested
to a person skilled in the art and are to be included within the
spirit and purview of this application. For example, while the use
of sonar energy has been described, it is contemplated that the
apparatus and method can be adapted to use laser energy, for
example.
* * * * *